On Fri, Dec 22, 2017 at 08:22:09PM +0530, Naresh Kamboju wrote: > On 22 December 2017 at 19:48, Dan Rue <dan.rue@xxxxxxxxxx> wrote: > > On Fri, Dec 22, 2017 at 09:45:08AM +0100, Greg Kroah-Hartman wrote: > >> 4.14-stable review patch. If anyone has any objections, please let me know. > >> > >> ------------------ > >> > >> From: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > >> > >> commit 83e3c48729d9ebb7af5a31a504f3fd6aff0348c4 upstream. > >> > >> Size of the mem_section[] array depends on the size of the physical address space. > >> > >> In preparation for boot-time switching between paging modes on x86-64 > >> we need to make the allocation of mem_section[] dynamic, because otherwise > >> we waste a lot of RAM: with CONFIG_NODE_SHIFT=10, mem_section[] size is 32kB > >> for 4-level paging and 2MB for 5-level paging mode. > >> > >> The patch allocates the array on the first call to sparse_memory_present_with_active_regions(). > >> > >> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > >> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > >> Cc: Borislav Petkov <bp@xxxxxxx> > >> Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxxx> > >> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > >> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > >> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > >> Cc: linux-mm@xxxxxxxxx > >> Link: http://lkml.kernel.org/r/20170929140821.37654-2-kirill.shutemov@xxxxxxxxxxxxxxx > >> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> > >> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > > > This patch causes a boot failure on arm64. > > > > Please drop this patch, or pick up the fix in: > > > > commit 629a359bdb0e0652a8227b4ff3125431995fec6e > > Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > > Date: Tue Nov 7 11:33:37 2017 +0300 > > > > mm/sparsemem: Fix ARM64 boot crash when CONFIG_SPARSEMEM_EXTREME=y > > > > See https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1527427.html > > +1. > Boot failed on arm64 without 629a359b > mm/sparsemem: Fix ARM64 boot crash when CONFIG_SPARSEMEM_EXTREME=y > > Boot Error log: > -------------------- > [ 0.000000] Unable to handle kernel NULL pointer dereference at > virtual address 00000000 > [ 0.000000] Mem abort info: > [ 0.000000] Exception class = DABT (current EL), IL = 32 bits > [ 0.000000] SET = 0, FnV = 0 > [ 0.000000] EA = 0, S1PTW = 0 > [ 0.000000] Data abort info: > [ 0.000000] ISV = 0, ISS = 0x00000004 > [ 0.000000] CM = 0, WnR = 0 > [ 0.000000] [0000000000000000] user address but active_mm is swapper > [ 0.000000] Internal error: Oops: 96000004 [#1] PREEMPT SMP > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.14.9-rc1 #1 > [ 0.000000] Hardware name: ARM Juno development board (r2) (DT) > [ 0.000000] task: ffff0000091d9380 task.stack: ffff0000091c0000 > [ 0.000000] PC is at memory_present+0x64/0xf4 > [ 0.000000] LR is at memory_present+0x38/0xf4 > [ 0.000000] pc : [<ffff0000090a1f54>] lr : [<ffff0000090a1f28>] > pstate: 800000c5 > [ 0.000000] sp : ffff0000091c3e80 > > More information, > https://pastebin.com/KambxUwb -rc2 is out with the fix, hopefully that survives longer :) thanks, greg k-h